Gold-catalyzed (4+3)-annulations of 2-alkenyl-1-alkynylbenzenes with anthranils with alkyne-dependent chemoselectivity: skeletal rearrangement <i>versus</i> non-rearrangement
作者:RahulKumar Rajmani Singh、Manisha Skaria、Liang-Yu Chen、Mu-Jeng Cheng、Rai-Shung Liu
DOI:10.1039/c8sc03619e
日期:——
Two distinct (4+3)-nitroxy annulations between 1,5-enynes and anthranils have been developed to access tetrahydro-1H-benzo[b]azepine derivatives; the chemoselectivity varies with the types of alkynes. Terminal alkyne substrates deliver benzo[b]azepine derivatives via a novel skeletal rearrangement while internal 1,5-enynes afford products without a rearrangement process. To elucidate the mechanism
已经开发了 1,5-烯炔和蒽醌之间的两种不同的 (4+3)-硝氧基环化来获得四氢-1 H-苯并[ b ] 氮杂卓衍生物;化学选择性因炔烃的类型而异。末端炔烃底物通过新的骨架重排提供苯并[ b ]氮杂衍生物,而内部 1,5-烯炔提供无需重排过程的产物。为了阐明重排的机制,我们进行了13 C-和2 H-标记实验来鉴定含金的异苯并富烯中间体,但它们的形成依赖于邻氨基苯甲酸的存在。
Gold-Catalyzed Oxidative Cyclization of 1,5-Enynes Using External Oxidants
作者:Dhananjayan Vasu、Hsiao-Hua Hung、Sabyasachi Bhunia、Sagar Ashok Gawade、Arindam Das、Rai-Shung Liu
DOI:10.1002/anie.201102581
日期:2011.7.18
Golden circle: Two gold‐catalyzed oxidativecyclizations of 1,5‐enynes using 8‐methylquinoline N‐oxide are presented (see example). Experimental results indicate that both reactions proceed through prior oxidation of alkyne to form α‐carbonyl intermediates and subsequent intramolecular carbocyclization.
Gold-Catalyzed Oxidative Cyclizations of 2-Oxiranyl-1-alkynylbenzenes for Diastereoselective Synthesis of Highly Substituted 2-Hydroxyindanones
作者:Rupsha Chaudhuri、Rai-Shung Liu
DOI:10.1002/adsc.201100325
日期:2011.10
We report the gold-catalyzedoxidativecyclizations of 2-oxiranyl-1-alkynylbenzenes into highlysubstituted 2-hydroxyindanone frameworks bearing a tertiary alcohol. Such gold-catalyzed reactions comprise an initial internal redox reaction, sulfoxide oxidation of α-carbonyl gold-carbenoids, followed by gold-catalyzed formal ene reactions on the resulting diketone intermediates.